Improvement in spark-arresters



D. HAWKESW'ORTH & COLFORD.

SPARK-ARRESTER. I I No.177',833. 1 Patented May 23,1876;

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Km PHOTO-UTHOGRAFHER, WASHINGTON. D, C-

UNITED STATES DANIEL HAWKESWORTH, 0F DIGBY, AND HENRY ooLF0RD,,onHALIFAX,

CANADA.

IMPROVEMENT m SPARK-ARRESTERS.

Specification forming part of Letters Patent No. 177.833, dated May 23,1876 application filed April 22, 1876.

ters of reference marked thereon, which form a part of thisspecification.

This invention relates to certain improvements in the spark-arrester forwhich Letters Patent of the United States No. 166,870 were granted toDaniel Hawke'sworth on the 17th day of August, 1875; and the saidimprovements consist in the combination, in the spark-arresting stack orcase, of one set of lower concaveor bent plates with an upper set offlat plates, substantially in the manner and for the purpose hereinaftermore fully described, and pointed out in the claim.

In the drawing, Figure 1 represents a longitudinal section of aspark-arrester showing this combination.

. A is theexterior box or case, which may be of any'suitableconfiguration, and a are the oircumferentially and spirally arrangedplates.

Those plates in the lower part of thecase A (denoted by a) are bent soas to form concave recesses (denoted by d) at the under side, for theinterception of soot and other solid products of combustion that arecarried off by the draft. We continue these concave or bent plates onlyso high up in the drum or stack A as is necessary to intercept the solidmatter which will be embedded in the cavities d; and above this set ofbent plates we place'a set of flat plates, similarly arranged, (denotedby a.) v I By this arrangement we not only'savematerial, (as it requiresless material to make the flat than the bent plates,') but the draft isimproved, because the flat plates in the upper part of the drum A do notoffer the same resistance to the draft passing through as the vbentplates in the lower part, which present a larger surface to the passingsmoke or air.

The plates at and a are fixed detachably to the inner sides of the drumor stack A by means of flanges b, affixed to the walls of the drum A,and projections b, that lit into the flanges, or by equivalent devices,so that the plates may be readily removed whenever it is desired toclean them.

In Fig. 2 we have representeda modifica- 1 tion of this combination ofconcave with flat plates. In this figure the lower concave plates do notreach to the axis of the drum A, within which theyare placed, butincrease. in size upward, so as to overlap each other, until the upperset of fiat plates are reached, which likewise increase in size, asshown in the drawing.

We prefer to use this construction in the I smoke-stacks of locomotivesburning Newcastle or other bituminous coal, this combination having thedouble advantage that the soot and all solid matter are intercepted bythe lower'bent plates a, which are so short as not to ofl'er anyresistance to the jets of steam,-

While the upper long plates willeffectually prevent the passage of anysparks that may pass by the lower short plates. 7

In Figs. 3, 4, and 5 we have shown various forms of the bent or concaveplates used in combination with this invention. These plates may eitherbe rounded 'or they may be bent at a sharp angle, the object beingsimply to providea cavity or recess, d, on the under side, into whichthe soot and solid products of combustion may be deposited, and fromwhich this may be readily removed, by a tool adapted-to the purpose,after the plates have been removed from the drum in which they areplaced.

Having thus described our invention, we claim and desire to secure byLetters Patent of the United States In a spark-arrester, heater, orsoot-gatherer, A, the combination of a lower set of removable concave orbent plates, a, with an upper set of flat plates, a, both sets of platesbeing arranged circumferentially and spirally, substantially in themanner and for the purpose hereinbefore set forth.

In testimony that we claim the foregoing as ourown we have heretoaffi-xeil our signatures in presence of two witnesses;

DANIEL HAWKESWORTH. HENRY COLFORD.

Witnesses to the signature of DANIEL HAWKESWORTH:

J. WM. RooP, W. H. AYMAR.

